The present invention is in the field of heat engines and is specifically directed to a device employing a temperature differential to create a variation in the density of the driving fluid. This fluid in turn drives the turbine.
The fundamental concept of heating a gas, using the increased energy of that gas to perform useful work and then recycling the gas for repeated use thereof has been known for many years. Two examples of such concepts are embodied in the Steriling and the Ericsson cycles. From these fundamental concepts, an almost unlimited number of devices and variations on devices have been developed to in one way or another turn the enrgy obtainable from a closed heat cycle into mechanical output. One such device worthy of mention in the present context is the disclosed in U.S. Pat. No. 2,597,249 to Paul Kollsman. This device employs a recycling gas subjected to a temperature differential across the mechanism. The entire mechanism functions much like a turbine with cooled gases passing outwardly on one side of the turbine and the heated gases passing inwardly on the other side of the turbine. As the heated gases move toward the axis, the change in angular momentum applies rotational energy to the engine. Another device using a liquid as the circulating fluid is disclosed in U.S. Pat. No. 4,022,024, to Abeles. This device employs gravity to operate on the variations in density of the recirculating liquid and employs a separate turbine to take off mechanical energy. The conventional recirculating fluid devices employing variable densities of the fluid as the driving force have been found to be relatively inefficient as is stated in the Abeles patent. Both the Kollsman and Abeles patents are directed to improvement in the efficiency of such systems.